Since the early nineteenth century the Naugatuck River Valley has been a center of brass product manufacturing. Waterbury inventors, concentrated in the brass industry, led all Connecticut cities in the number of patents issued per resident. Hiram W. Hayden (b. Haydenville, Massachusetts; 1820-1904), a machinist employed by the Scoville Company, invented in 1851 a method of making brass kettles by spinning disks of sheet brass through a die. Machinist Eli J. Manville of Watertown (1823-1886) invented an automatic wire-forming machine. In the twentieth century engineers at the company he founded developed many machines that automatically produced brass parts used in automobiles.